With development of photoelectric acquisition technologies and continuous increase of requirements for high-definition digital videos, an amount of video data is increasingly large. Due to limited heterogeneous transmission bandwidths and diversified video applications, higher requirements are continuously imposed on video coding efficiency. A task of developing a High Efficiency Video Coding (HEVC) standard is initiated according to the requirements.
A basic principle of video compression coding is to use correlation between a space domain, a time domain, and a code word to remove redundancy as much as possible. Currently, a prevalent practice is to use a block-based hybrid video coding framework to implement video compression coding by performing steps of prediction (including intra-frame prediction and inter-frame prediction), transform, quantization, entropy coding, and the like. In an intra-frame prediction technology, redundancy information of a current picture block is removed by using spatial pixel information of the current picture block, to obtain a residual; in an inter-frame prediction technology, redundancy information of a current picture block is removed by using pixel information of a coded or decoded picture adjacent to a current picture block, to obtain a residual. This coding framework shows high viability, and therefore, HEVC still uses this block-based hybrid video coding framework.
In the prior art, a method for predicting a pixel value of a current picture block based on a non-local means filtering technology is provided. After all templates matching a current template are obtained by searching reference pictures, a predicted pixel value of a current picture block is obtained by using an average of pixel values of picture blocks corresponding to the all templates. However, in a test and practice process, it is found that, sometimes, prediction accuracy in an existing prediction technology is relatively low, and consequently, this is likely to affect video coding and decoding quality.